安装：https://getcomposer.org/download/
{
"require":{
// "厂商/类库":"版本号",
"smarty/smarty":"3.1.31",
}
}
新增：composer install
修改：composer update
卸载：composer remove "厂商/类库"
更新文件：composer dump-auto
配置全局composer：
mv composer.phar /usr/local/bin/composer
composer self-update